Electromagnetic shielding, such as radiofrequency (RF) shielding, is commonly provided over circuitry components, for example provided on a portion of a printed circuit board (PCB). The conductive enclosure provided by such shielding helps to electromagnetically isolate the circuitry inside the enclosure from the environment outside. Electromagnetic shielding is particularly useful for devices having RF communication capabilities, for example in order to electromagnetically isolate RF components such as antennas and transmission lines from other components such as digital components.
Various models of electromagnetic shields for mounting to PCBs include separate sidewall and lid components, which can be known in the art as multi-part shields. With the lid is disengaged, the area enclosed by the sidewalls can be accessed, in order to populate circuits to the PCB, test, adjust and repair the circuits, and the like. The lid may then be removably or non-removably engaged with the sidewalls. This option can be attractive as it offers improved ease of access to the shielded components.
However, as the lid is not integrally formed with the sidewalls, various problems may arise if the shield is mechanically deformed, for example as illustrated in FIG. 1. For example, due to an unintentional drop or intentional drop test, the shield sidewalls may become permanently deformed. This deformation may introduce gaps between the sidewalls and the lid or allow the lid to move with respect to the sidewalls. This may allow RF leakage through the shield and spurious RF emissions, which may be undesirable and potentially may result in safety or performance issues.
Examples of existing multipart shields are described for example in U.S. Pat. Nos. 6,552,261, 7,109,411, 7,623,360 and United States Patent Application Publication Nos. 2007/0139904, 2008/0080160 and 2011/0094791. However, these shielding solutions lack a desirable combination of structural integrity and simplicity. Furthermore, additional shielding solutions would advantageously provide for more choices during product design.
Therefore there is a need for an electromagnetic shield that is not subject to one or more limitations of the prior art.
This background information is provided for the purpose of making known information believed by the applicant to be of possible relevance to the present technology. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present technology.